I was able to use micro TL-WN725N v2 WiFi module successfully with ODROID U2 & connect to WPA2-PSK protected AP.
Since the driver is not available off-the-shelf, one needs to recompile the module driver source using correct kernel version sources.
My OS is the official Debian Wheezy distro availble from here: http://forum.odroid.com/viewtopic.php?f=9&t=1608

If you see something like:8188eu: version magic '3.8.13.4 SMP preempt mod_unload ARMv7 p2v8 ' should be '3.8.13.3 SMP preempt mod_unload ARMv7 p2v8 '
This means that the OS kernel version and used kernel source version differs (see step 1 to update OS kernel version to latest version, re-check kernel source version, repeat all the build steps). If it still does not work, try removing version information & re-copy new driver file to module directory:

I am a linux newbie as well as a Odroid newbie. I have a U3 that I received this week. I have run the above code and I can't get the Dongle running. I am using the 14.04.2 IMG from the Odroid site. I opened the browser on the U3 so I could copy/paste the code so as not to miss anything. I am a little hemmed in by the HDMI+Ethernet combo. I only have a short time to try to get the wifi connected then I have to take down my setup.

I get to the 3rd part of step 8-- CONFIG_RTL8188EU=m make -C /usr/src/linux M=`pwd` in the out in the terminal I get these lines--

Kernel configuration is invalid.
include/generated/autoconf.h or include/config/auto.conf are missing.
Run 'make oldconfig && make prepare' on kernel src to fix it.

What will I need to post the next time to help discover my problem?
Do I use the above code as written or do I need to change references? I see that the OP uses WHeezy.
Thanks for any help you may be able to provide.

EDIT**** I got it working!! What I found was if I left out the steps in box 4

# see which ODROID configuration files are availabe to you and copy the required one to the source directory
ll arch/arm/configs
cp arch/arm/configs/odroidu2_defconfig ./.config

Then it ran and compiled a driver the very first time I ran it. If I used those commands then I got errors. I have connected and am updating software through this Wifi dongle now. This for U3 using the Ubuntu 14.04.2 IMG from 2/25/15.

Hi!
Big thanks for the post, it helped me. I want to add, that it can be important to use 7z tool to unzip the sources, because unzip messed up the Kconf files for me.
If anyone is interested, I uploaded a working version for Odroid-U3 with kernel version 3.8.13.30.
download link: https://www.dropbox.com/s/1my2ubiip4ive ... eu.ko?dl=0
Cheers,
Marci